U.S. Pat. No. 4,708,084 and U.S. Pat. No. 4,948,095 are hereby incorporated by reference into this disclosure.
The invention relates generally to a water distribution system for directing the flow of water between a reservoir, such as a livewell on a fishing boat, and a water source, such as a lake or river.
The water distribution systems disclosed in U.S. Pat. Nos. 4,589,441 and 4,708,084 represent typical prior art apparatus for controlling the flow of water between a livewell and an external water source. These systems are used widely by many manufacturers of sport fishing boats. They achieve various advantages such as use of only a single pump to both fill the livewell and recirculate livewell water through the system's aeration device; and, the ability, when the boat is running, to automatically prevent loss of livewell water out the drain port, while continuing to draw water from the livewell drain for recirculation and aeration.
However, while commercially successful, the water distribution systems described in U.S. Pat. Nos. 4,589,411 and 4,708,084 nonetheless suffer from various disadvantages. For example, these prior art systems cannot prevent outside water from being drawn into the livewell by the aerator pump while the boat is still or moving slowly. This "recirculate-only" mode is desirable to prevent drawing hot or muddy water into the livewell when fishing shallow water. It also can be used, to cite another example, when chemicals, such as tranquilizers or ph treatments, are to be added to the livewell without diluting the chemical's effectiveness.
There are also situations in which the flapper valve described in U.S. Pat. Nos. 4,589,441 and 4,708,084 is too flexible to prevent a loss of water. For instance, when the boat is running in rough water, an oscillating pressure wave can occur in the livewell drain. This can cause the flapper to oscillate between open and closed positions, allowing a significant amount of water to leak from the livewell during long runs. Leakage can also occur when the boat is out of the water, as the pump suction can lift the flapper from sealing contact with its valve seat.
It would therefore be desireable to provide a water distribution system for a livewell which could operate in a "recirculate-only" mode, and which would overcome the effect of pressure oscillations in the drain line and resist the suction created by the aerator pump.